I'm trying to map integer $x$ to the set of all (ordered) $n$-tuples of positive integers that sum to it.
$ f_n(x): \Bbb{Z} \to \cal{P}\left({\Bbb{Z}^{+}}^{n}\right) = \left\{\left(i_1,\dots,i_n\right)\right |\sum{i_k}=x\}$
Is there a name for this (admittedly partial) function?
Example:
$ (3, 5) \mapsto \left\{\left(1, 1, 3\right), \left(1, 2, 2\right), \left(1, 3, 1\right), \left(2, 1, 2\right), \left(2, 2, 1\right), \left(3, 1, 1\right)\right\} $